Effect of dynamic light at the coronary care unit on the length of hospital stay and development of delirium: a retrospective cohort study.

BACKGROUND: Disturbed circadian rhythm is a potential cause of delirium and is linked to disorganisation of the circadian rhythmicity. Dynamic light (DL) could reset the circadian rhythm by activation of the suprachiasmatic nucleus to prevent delirium. Evidence regarding the effects of light therapy is predominantly focused on psychiatric disorders and circadian rhythm sleep disorders. In this study, we investigated the effect of DL on the total hospital length of stay (LOS) and occurrence of delirium in patients admitted to the Coronary Care Unit (CCU). METHODS: = 379). DL was administered at the CCU by two ceiling-mounted light panels delivering light with a colour temperature between 2700 and 6500 degrees Kelvin. Reported outcome data were: total hospital LOS, delirium incidence, consultation of a geriatrician and the amount of prescripted antipsychotics. No significant differences between the DL and control group were observed in secondary endpoints. Subgroup analysis based on age and CCU LOS also showed no differences. CONCLUSION: Our study suggests exposure to DL as an early single approach does not result in a reduction of total hospital LOS or reduced incidence of delirium. When delirium was diagnosed, it was associated with poor hospital outcome.